Dual radiator engine cooling module - single coolant loop

ABSTRACT

An engine cooling system for a motor vehicle having a dual radiator assembly plumbed in parallel within a single coolant loop to provide improved engine cooling.

FIELD

The present disclosure relates generally to engine cooling systems formotor vehicles and, more particularly, to a single loop dual radiatorcooling module for such engine cooling systems.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

As motor vehicles continue to require more towing capacity and enginecooling for optimal performance and to meet stringent emissionsregulations, the heat rejection requirements from the engine into thecoolant rises. As such, the use of larger radiators is necessary to meetthe increased heat rejection requirements. Unfortunately, the packagingspace available in front of the engine within the engine compartment islimited and does not always permit the use of larger radiators. Inaddition, since it is a conventional practice to include the radiator,blower fan, and condenser of the motor vehicle's HVAC system into apre-assembled condenser, radiator and fan module (CRFM) assembly, it isusually impractical to increase the radiator's thickness.

In an effort to address this situation, it is known to use two radiatorsin a cooling system that is configured to split the heat rejectionrequirements between a first cooling circuit for engine cooling and asecond cooling circuit for auxiliary component cooling, such astransmission oil and/or EGR cooling. Unfortunately, such dual radiatorcooling systems require that a separate water pump be provided inconjunction with each of the independent cooling circuits. Accordingly,there remains a need in the art to overcome the limitations of prior artvehicle cooling systems and provide cost-effective alternatives thatmeet the packaging and heat rejection requirements of modern motorvehicles.

SUMMARY

This section provides a general summary of the present disclosure, andis not a comprehensive disclosure of its full scope or all of itsfeatures and advantages.

It is an aspect of the present disclosure to provide a dual radiatormodule having first and second radiators that are plumbed in paralleland which is adapted for use with a vehicular cooling system having asingle water pump.

It is a related aspect of the present disclosure to provide such a dualradiator module having a larger first radiator located in front of thevehicle's cooling fan and a smaller second radiator disposed between thefirst radiator and a condenser of the vehicle's HVAC system.

In accordance with these and other aspects of the present disclosure, adual radiator module is provided which is adapted to fit into availablepackaging spaces, has lower air restriction values compared to thicksingle radiator modules, and which is configured for use with a singlewater pump for common coolant flow to both radiators.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected exemplary embodiments and are not intended to limit the scopeof the present disclosure in any way. Similar or identical elements aregiven consistent reference numerals throughout the various figures.

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings wherein:

FIG. 1 is a diagrammatical view of a cooling system for use in a motorvehicle and which is equipped with a dual radiator module constructed inaccordance with the present teachings;

FIG. 2 is a rear perspective view of the dual radiator moduleconstructed in accordance with an exemplary embodiment of the presentdisclosure;

FIG. 3 is a front perspective view of the dual radiator module of thepresent disclosure:

FIG. 4 is a top perspective view of the dual radiator module of thepresent disclosure;

FIG. 5 is a cross-sectional view illustrating an arrangement of thecomponents associated with the cooling system equipped with the dualradiator module; and

FIG. 6 is a cross-sectional view illustrating an alternative arrangementof the components of the cooling system having the dual radiator module.

DETAILED DESCRIPTION

Referring to FIG. 1, a cooling system 10 for use in a motor vehicle 12is schematically shown. Cooling system 10 is operable for thermallymanaging various components of motor vehicle 12. To this end, coolingsystem 10 includes a first or primary fluid circuit 14 and a second orauxiliary fluid circuit 16. First fluid circuit 14 is configured tothermally manage an internal combustion engine 18 of motor vehicle 12while second fluid circuit 16 is configured to thermally manage one ormore auxiliary components 20 associated with motor vehicle 12. Coolingsystem 10 includes a pump 22 integrated into both fluid circuits 14, 16that is operable to pump a common coolant therethrough. As such, fluidcircuits 14, 16 share a common supply of coolant. An expansion tank (notshown) may be included to receive coolant overflow from the radiatorsassociated with each of the fluid circuits 14, 16.

First fluid circuit 14 is configured to thermostatically manage thetemperature of engine 18. Coolant is supplied by pump 22 to a first heatexchanging device 24 associated with engine 18. For example, first heatexchanging device 24 can include a coolant jacket of engine 18 that isconfigured to circulate coolant about and through engine 18 to transferheat between engine 18 and the coolant for selectively heating orcooling engine 18. Downstream from first heat exchanging device 24 is afirst thermostatic valve or thermostat 26 which selectively directscoolant between a first or primary radiator module 28 and a firstradiator bypass 30 parallel to first radiator module 28 in response tothe coolant temperature. First thermostat 26 includes an inlet 32 influid communication with an outlet 34 of first heat exchanging device24, a first outlet 36 in fluid communication with an inlet 38 to firstradiator module 28, and a second outlet 40 in fluid communication withan inlet 42 to first bypass 30.

When the temperature of the coolant is below a first predefinedtemperature value, first thermostat 26 functions to direct coolantthrough first bypass 30 back to pump 22 so that the coolant bypassesfirst radiator module 28 and can be used, for example, in warming-upengine 18 during cold starts. Once the coolant has reached the firstpredefined coolant temperature value, first thermostat 26 begins to openand allows flow of the coolant to first radiator module 28 fortransferring heat out of the coolant and into air flowing past firstradiator module 28. The flow of air past first radiator module 28results from operation of an onboard cooling fan 44 and/or movement ofmotor vehicle 12. Fan 44 can be driven by engine 18 through an accessorydrive system or can, in the alternative, be a motor-driven unit. As thecoolant temperature increases, first thermostat 26 continues to opensuch that all, or a substantial amount of the coolant discharged fromfirst heat exchanging device 24 flows to first radiator module 28 forcooling engine 18 to a desired operating temperature.

A portion of the coolant supplied to pump 22 is delivered to secondfluid circuit 16 and flows to an inlet 46 of a second thermostatic valveor thermostat 48. Second thermostat 48 selectively directs the coolantbetween a second radiator module 50 and a second radiator bypass 52 inparallel thereto in response to the coolant temperature. As such, secondthermostat 48 has a first outlet 54 in fluid communication with secondradiator module 50 and a second outlet 56 in fluid communication withsecond radiator bypass 52. Second thermostat 48 is configured to directthe coolant to second bypass 52 when the coolant temperature is below asecond predefined temperature value. In such case, all or a substantialamount of the coolant flows through second bypass 52 to one or moresecond heat exchanging devices 58, thereby bypassing second radiatormodule 50. This arrangement is also useful during cold-start conditionswhen the auxiliary components 20 are relatively cold. Thus, use ofsecond bypass 52 enables relatively quick warming of auxiliarycomponents 20 when required to enhance performance of vehicle 12.

Once the coolant reaches the second predefined temperature value, secondthermostat 48 starts to open inlet 54 and allows coolant to flow tosecond heat exchanging devices 58 through second radiator module 50.Coolant flowing through second radiator module 50 is cooled due to heattransferred from the coolant to air flowing past second radiator module50 which may be located forward or aft of first radiator module 28 tobenefit from the air flow resulting from operation of cooling fan 44and/or movement of vehicle 12. With increasing coolant temperature,second thermostat 48 continues to open inlet 54 allowing more coolant toflow through second radiator module 50 to second heat exchanging devices58. Second thermostat 48 may be configured such that eventually most, ifnot all, of the coolant in second fluid circuit 16 flows through secondradiator module 50.

Coolant discharged from second radiator module 50 and second bypass 52flows to one or more of second heat exchanging devices 58. For example,second heat exchanging devices 58 may include, but not be limited to,one or more charged air coolers (CAC) for cooling engine intake aircharged by a turbo/supercharger, one or more hydraulic oil coolers suchas a power steering oil cooler (PSOC) and/or a transmission oil cooler(TOC). As such, auxiliary components 20 may include, but not be limitedto charge air for engine intake air, hydraulic oil for hydraulicfunctions onboard vehicle 12 and/or transmission oil for a transmissionassociated with the powertrain of vehicle 12. After passing throughsecond heat exchanging devices 58, the coolant flows back to pump 22.

In second fluid circuit 16, the coolant is always able to flow to secondheat exchanging devices 58 during operation of vehicle 12 regardless oftemperature, either through second bypass 52, second radiator module 50,or both. This enable second fluid circuit 16 to respond quickly toinstantaneous heat loads of auxiliary components 20 at one of more ofsecond heat exchanging devices 58 (i.e., charge air cooler, hydraulicoil cooler, transmission oil cooler) to cool such heat loads relativelyquickly.

By fluidly connecting first fluid circuit 14 and second fluid circuit 16via a common pump 22, the coolant is able to flow therebetween. As aresult, first radiator module 28 of first fluid circuit 14 is able toadd cooling capacity to second radiator module 50 of second fluidcircuit 16, thereby allowing use of a smaller second radiator module 50.

In general, the present disclosure is directed to optimizing the heattransfer characteristics of first radiator module 28 for providingsuperior engine cooling. To this end, first radiator module 28 isconfigured as a dual radiator assembly 80 having a first radiator unit100 and a second radiator unit 102. Each of the first and secondradiator units have a reduced core thickness that, when plumbed inparallel, function to provide equal or greater cooling capacity incomparison to conventional single radiator units. In accordance withthis aspect, a preferred construction of one exemplary embodiment ofdual radiator assembly 80 will now be described in greater detail.

Referring now to FIGS. 2 through 4, an exemplary construction of firstradiator module 28 in accordance with the present teachings is shown toinclude dual radiator assembly 80 having first radiator unit 100, secondradiator unit 102, an upper inlet hose assembly 104 and a lower outlethose assembly 106. In general, first radiator unit 100 and secondradiator unit 102 are plumbed in parallel to establish dual radiatorassembly 80 that is configured for use with first fluid circuit 14 incooling system 10, as shown in FIG. 1.

Inlet hose assembly 104 can include a first inlet hose 108, a secondinlet hose 110, a Y-joint inlet connector 112, and an inlet supply tube114. One end of first inlet hose 108 is connected to an inlet port 116of an inlet tank 117 associated with first radiator unit 100 while itsopposite end is connected to one junction 112 a of inlet connector 112.Similarly, one end of second inlet hose 110 is connected to an inletport 118 of an inlet tank 119 associated with second radiator unit 102while its opposite end is connected to a second junction 112 b of inletconnector 112. Supply tube 114 is adapted to provide fluid communicationvia a hose (not shown) between outlet 36 of first thermostat 26 and acommon inlet 112 c of inlet connector 112. Accordingly, coolant flowingfrom first heat exchanger 24 through first thermostat 26 is suppliedthrough inlet hose assembly 104 to the inlet tanks 117,119 of bothradiator units 100, 102 associated with dual radiator assembly 80.

Outlet hose assembly 106 can include a first outlet hose or coupling120, a second outlet hose or coupling 122, a Y-joint outlet connector124, and an outlet supply tube 126. One end of first outlet hose orcoupling 120 is connected to an outlet port 128 of an outlet tank 129associated with first radiator unit 100 while its opposite end isconnected to one junction 124 a of outlet connector 124. Similarly, oneend of second outlet hose or coupling 122 is connected to an outlet port130 of an outlet tank 131 associated with second radiator unit 102 whileits opposite end is connected to a second junction 124 b of outletconnector 124. Outlet supply tube 126 is adapted to provide fluidcommunication via a hose (not shown) between a common inlet 124 c ofoutlet connector 124 and pump 22. Accordingly, the coolant dischargedfrom the outlets of dual radiator assembly 80 is supplied to pump 22.

In comparison to a conventional single radiator type of first radiatormodule commonly associated with prior art engine cooling systems, dualradiator assembly 80 utilizes a pair of radiator units 100,102 havingreduced core thicknesses yet an increased total cross-sectional area toprovide the required heat transfer characteristics. Such thinnerradiator units 100,102 also produce less airflow restriction (air-sidepressure drop) to cooling system 10. Additionally, the plumbing of dualradiator assembly 80 in such a parallel arrangement with common inletand outlet hoses permits use of a single water pump 22.

In accordance to one exemplary packaging arrangement, dual radiatorassembly 80 is configured to generally locate a larger first largerradiator unit 100 in a conventional position in front of cooling fan 44while a smaller second radiator unit 102 is located in the availablevehicle packaging space either forward or aft of first radiator unit100. In accordance with a specific exemplary configuration for dualradiator assembly 80, first radiator unit 100 can have a 27 mm coredepth and second radiator unit 102 can have a 27 mm core depth and belocated in front of first radiator unit 100 right below the hood line ofvehicle 12. Such an arrangement is shown in FIG. 5 to further includeauxiliary components 20 associated with second fluid circuit 16 whichcan include charged-air cooler 20A and an oil cooler 20B. A condenser 88associated with the vehicle's HVAC system is shown located forward ofdual radiator assembly 80. An alternative arrangement is shown in FIG. 6wherein greater spacing is provided between first radiator unit 100 andsecond radiator unit 102 and charged-air cooler 20A is located out ofthe radiator airstream. As will be appreciated, first radiator unit 100and second radiator unit 102 are plumbed in parallel regardless of thepackage spacing or orientation therebetween.

What is claimed is:
 1. A radiator assembly for use in an engine coolingsystem of a motor vehicle, comprising: a first radiator unit having afirst inlet and a first outlet; a second radiator unit having a secondinlet and a second outlet; an inlet hose assembly having a first inlethose connected to said first inlet, a second inlet hose connected tosaid second inlet, an inlet supply hose, and an inlet connectorinterconnecting said inlet supply hose to both of said first and secondinlet hoses; and an outlet hose assembly having a first outlet hoseconnected to said first outlet, a second outlet hose connected to saidsecond outlet, an outlet supply hose, and an outlet connectorinterconnecting said outlet supply hose to both of said first and secondoutlet hoses.
 2. The radiator assembly of claim 1 wherein said firstradiator unit is larger than said second radiator unit.
 3. The radiatorassembly of claim 1 wherein a thickness dimension of a first core forsaid first radiator unit is equal to a thickness dimension of a secondcore for said second radiator unit.
 4. The radiator assembly of claim 1wherein said first radiator unit is disposed between a blower fan andsaid second radiator unit.
 5. The radiator assembly of claim 1 whereinsaid inlet hose assembly is supplied with coolant exiting the engine andsaid outlet hose assembly supplies coolant to a water pump.
 6. Aradiator assembly for use in an engine cooling system of a motor vehiclehaving a water pump and a fluid flow circuit through which coolant iscirculated between the engine and the water pump, the radiator assemblycomprising: a first radiator unit having a first inlet and a firstoutlet; a second radiator having a second inlet and a second outlet; aninlet hose assembly having an inlet supply hose in fluid communicationwith the fluid flow circuit to receive coolant from the engine, a firstinlet hose connecting said inlet supply hose to said first inlet, and asecond inlet hose connecting said inlet supply hose to said secondinlet, and an outlet hose assembly having an outlet supply hose in fluidcommunication with the fluid flow circuit to supply coolant to the waterpump, a first outlet hose connecting said outlet supply hose to saidfirst outlet, and a second outlet hose connecting said outlet supplyhose to said second outlet.
 7. The radiator assembly of claim 6 whereinsaid first radiator unit is larger than said second radiator unit. 8.The radiator assembly of claim 6 wherein a thickness dimension of afirst core for said first radiator unit is equal to a thicknessdimension of a second core for said second radiator unit.
 9. Theradiator assembly of claim 6 wherein said first radiator unit isdisposed between a blower fan and said second radiator unit.
 10. Theradiator assembly of claim 6 wherein said inlet hose assembly includesan inlet coupling interconnecting said inlet supply hose to said firstand second supply hoses, and wherein said outlet hose assembly includesan outlet coupling interconnecting said outlet supply hose to said firstand second outlet hoses.